1. Field of the Invention
The present invention relates to apparatus for successively treating a substance carried upon or affixed to a surface of a continuous ribbon or tape with different treating liquids, by advancing such tape through a series of such liquids, and finds particular application in the treatment for microscopic examination of biological smears deposited on a tape, as described in U.S. Ser. No. 375,223, now U.S. Pat. No. 3,861,197, assigned to the assignee of the present invention. However, the invention finds broad application in those cases where substances carried upon or affixed to a continuous surface or sequential surface areas are to be successively treated by a plurality of liquids.
2. Prior Art
Heretofore, biological substances have been prepared for microscopic examination by applying or smearing the same onto glass microscopic slides, by known techniques. Subsequently, these biological smears were subjected to various procedures, according to the particular effect desired, to stain the various cells and facilitate differentiation of different cell types while examined under a microscope by an examiner. Such staining procedure required that the smear be treated by exposing the same to various liquids including dyes, e.g., thiazine dyes, oxazine dyes, etc. Such procedure, when done manually, necessitated that the smear be exposed to air between successive dippings and washings in the various liquid reactants by the operator. Conventionally, a microscopic slide, with the smear affixed to one surface, is dipped successively into a plurality of liquid reactants for predetermined time intervals and then washed. Depending upon the particular staining procedure, as many as ten or twelve liquid reactants might be required. Such manually performed prior art treatment of biological smears was time consuming. Also, there was considerable danger of carryover between the liquid reactants by the microscopic slides and frequent recycling of the liquid reactants was necessary.
In U.S. Pat. No. 3,431,886, there is shown an apparatus for the automatic staining of microscopic slides, by effectively contacting the biological smear carried thereon with a plurality of liquid reactants, in turn. Such apparatus operates to move the slide through a number of treatment stations, whereat the surface of the slides carrying the biological smear is exposed to a metered quantity of unused reactants.
In U.S. Ser. No. 375,223, an apparatus is particularly disclosed for depositing biological smears onto a ribbon or tape, which is not particularly susceptible to treatment by conventional prior art techniques. The present invention finds particular application in the treatment of such biological smears disposed successively.